An Open Label Extension Study to Assess Long-Term Safety of Eplontersen in Adults With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM)

An Open-Label Extension Study to Assess the Long-Term Safety of Eplontersen (ION-682884) in Patients With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM)

Status

Recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2071250030

Enrollment

Registered

2025-06-04

Start date

2025-06-11

Completion date

Unknown

Last updated

2025-07-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM)

Interventions

Study drug: Eplontersen(ION-682884) eplontersen SC once every month for up to 36 months(36 months OR 6 months after eplontersen is health authority-approved and available in the site's country,whichev

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Satisfactory completion of Treatment Period and the End of Treatment Visit of the Index Study (ION-682884-CS2) OR diagnosis of ATTR-CM and satisfactory participation on ISIS 420915- CS101 study as judged by the Investigator and Sponsor. 2. Investigator is willing to treat the participant with open-label eplontersen. 3. Willingness to adhere to vitamin A supplementation per protocol.

Exclusion criteria

Exclusion criteria: 1. Permanently discontinued study drug administration while participating in the Index Study (ION 682884-CS2) or IST (ISIS 420915-CS101 Study). 2. Have any new condition or worsening of an existing condition that in the opinion of the Investigator or Sponsor would make the participant unsuitable for enrolment, or which could interfere with the participant participating in or completing the study, including the need for treatment with medications disallowed in the Index Study.

Design outcomes

Primary

Measure	Time frame
Number of Participants With Adverse Events (AE) and Serious Adverse Events (SAE) [Time Frame: Baseline up to 36 months] Change From Baseline in Platelet Count [Time Frame: Baseline up to 36 months] Change From Baseline in Estimated Glomerular Filtration Rate (eGFR) [Time Frame: Baseline up to 36 months] Change From Baseline in Urine Protein Creatinine Ratio (UPCR) [Time Frame: Baseline up to 36 months] Change From Baseline in AST [Time Frame: Baseline up to 36 months] Change From Baseline in ALT [Time Frame: Baseline up to 36 months] Number of Participants With Clinically Significant Changes From Baseline in Electrocardiogram (ECG) Parameters [Time Frame: Baseline up to 36 months] Number of Participants With Clinically Significant Changes From Baseline in Thyroid-Stimulating Hormone (TSH) [Time Frame: Baseline up to 36 months] Percentage of Participants With Anti-Drug Antibodies (ADA) [Time Frame: Baseline up to 36 months]	—

Measure

Time frame

Number of Participants With Adverse Events (AE) and Serious Adverse Events (SAE) [Time Frame: Baseline up to 36 months] Change From Baseline in Platelet Count [Time Frame: Baseline up to 36 months] Change From Baseline in Estimated Glomerular Filtration Rate (eGFR) [Time Frame: Baseline up to 36 months] Change From Baseline in Urine Protein Creatinine Ratio (UPCR) [Time Frame: Baseline up to 36 months] Change From Baseline in AST [Time Frame: Baseline up to 36 months] Change From Baseline in ALT [Time Frame: Baseline up to 36 months] Number of Participants With Clinically Significant Changes From Baseline in Electrocardiogram (ECG) Parameters [Time Frame: Baseline up to 36 months] Number of Participants With Clinically Significant Changes From Baseline in Thyroid-Stimulating Hormone (TSH) [Time Frame: Baseline up to 36 months] Percentage of Participants With Anti-Drug Antibodies (ADA) [Time Frame: Baseline up to 36 months]

—

Secondary

Measure	Time frame
Change From Baseline in Transthyretin (TTR) Serum Levels [Time Frame: Baseline up to 36 months] Change From Baseline in 6-minute Walk Test (6MWT) [Time Frame: Baseline up to 36 months] Change From Baseline in Kansas City Cardiomyopathy Questionnaire (KCCQ) [Time Frame: Baseline up to 36 months] Change From Baseline in Short Form Health Survey Questionnaire (SF-36) [Time Frame: Baseline up to 36 months] Change From Baseline in 5 Level EuroQol - 5 Dimension (EQ-5D-5L) [Time Frame: Baseline up to 36 months] Change From Baseline in Biomarker: N-terminal prohormone of Brain Natriuretic Peptide (NT-proBNP) [Time Frame: Baseline up to 36 months] Change From Baseline in Biomarker: High Sensitivity Cardiac Troponin T (hs-cTnT) [Time Frame: Baseline up to 36 months]	—

Measure

Time frame

Change From Baseline in Transthyretin (TTR) Serum Levels [Time Frame: Baseline up to 36 months] Change From Baseline in 6-minute Walk Test (6MWT) [Time Frame: Baseline up to 36 months] Change From Baseline in Kansas City Cardiomyopathy Questionnaire (KCCQ) [Time Frame: Baseline up to 36 months] Change From Baseline in Short Form Health Survey Questionnaire (SF-36) [Time Frame: Baseline up to 36 months] Change From Baseline in 5 Level EuroQol - 5 Dimension (EQ-5D-5L) [Time Frame: Baseline up to 36 months] Change From Baseline in Biomarker: N-terminal prohormone of Brain Natriuretic Peptide (NT-proBNP) [Time Frame: Baseline up to 36 months] Change From Baseline in Biomarker: High Sensitivity Cardiac Troponin T (hs-cTnT) [Time Frame: Baseline up to 36 months]

—

Countries

Argentina, Australia, Austria, Belgium, Brazil, Canada, Czechia, Denmark, France, Germany, Greece, Israel, Italy, Japan, Poland, Portugal, Spain, Sweden, United Kingdom, United States

Contacts

Public Contactcontact Clinical trial

ICON Clinical Research GK

ICONCR-Chiken@iconplc.com+81-6-4560-2001

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Feb 4, 2026